Osteoarthritis is characterized by chronic degradation of articular cartilage in the afflicted joints. Histochemical and biochemical findings suggest that increased levels of lysosomal enzymes are associated with the breakdown of proteoglycans, the principal extracellular constituents. Arylsulfatases A and B, in particular, have been shown to be elevated in the articular cartilage derived from individuals with osteoarthritis. Physiological, regulatory, and physical-chemical properties of these two arylsulfatases purified from human articular cartilage will be investigated with a view to discerning differences in sulfated glycolipid and proteoglycan metabolism in normal and pathologic tissues. These enzymes will also be purified from chondrocyte cultures and the effect on their activities by varying concentrations of ascorbic acid will be measured. The effect of ascorbic acid on sulfated proteoglycan and collagen metabolism in chondrocyte cultures also will be investigated. Normal and osteoarthritic human sera will be fractionated in order to isolate those factors responsible for modulating the biosynthesis, distribution, and degradation of sulfated proteoglycans and collagen in chondrocyte cultures. In an effort to correlate sulfated proteoglycan catabolism with the severity of the degenerative process, studies aimed at elucidating the degradative pathway of these macromolecules in articulr cartilage will continue. The molecular size and chemical compositions of the intermediate and final breakdown products will be determined.